TFight 320 VO2 - Need string advice

I have new TFight racquet. My first string job was Pro Line II (1.25) at 55/53 Lbs. Racquet played very well at the start, but after about 2.5 hour mark, tension suddenly dropped and then i had hard time to keep ball inside the court.
I have never experienced so quick tension drop. PL II does not have best tension maintenance out there, but it keeps playability much longer in my other frames.

So, is it faster tension loss in TFight racquets common ?
Is it product of such open string pattern ?
I usually use 1.25 gauge strings in my racquets, should i try 1.30 for this one ?
What are the good polys for this racquet and what tension ?
Anyone tried SP Hyperion in this racquet ?

Pro Red Code 1.25 mains @55 / Isospeed Baseline Spin 1.18 x @55
Staying strong for 5 hours now, nice power/control and touch is superb.
There is room to go tigther may be even to 60 if you prefer more boardy because the baseline really soften the string bed.

Of all the strings I've tried in mine I like RPM Blast at low tension (40lbs) the best. The lower tension really pockets the ball and can really put some great topspin on the ball. Also, counterintuitively, the lower tension reigns in some of the power of this stick.